Plasma sclerostin level and, the right and left knee flexor and extensor muscles strength will be measured before and after training period. Isokinetic torque will be measured with the Biodex (Biodex System 3 PRO Multijoint System Biodex Medical Inc. Shirley/NY USA)extremity-testing system. The right and left lower limbs bone mineral density (BMD) and muscle strength will be measured before training period. The BMD will be evaluated by bone densitometer (Norland XR-46 DXA, USA). Sclerostin levels will be measured by human sclerostin ELISA kit.